So let's dig into this. I think we can have a constructive discussion.
Not an opinion: The Ultimate license, which a gamemaster needs to run a table without his players paying anything, costs $10/month or $149 flat. This includes no game content that isn't available for free elsewhere, just their VTT and campaign management machinery. It's worth noting that their free service doesn't even include that game content that is available for free elsewhere -- they gate that behind a lower price point. Running a game on Roll20 is, by comparison, free to all, with minor cosmetic limitations on the free license, and does include game content available for free elsewhere.
Yep, FG ultimate license is 10/149 as you outlined. But that doesn't tell the whole story does it?
Free game content; Nope, not true, their is free game content for numerous game systems (D&D 1e, 3, 3.5, 5e, PF, Savage World, etc) available for free on their community forums and some for 5E on the DMsGuild. It is, admittedly, only a tiny fraction of what is available world-wide.
Of course, all that free stuff can easily be ripped from PDF or other formats and dropped into FG with what I'm told is less work than it takes to do the same for Roll20 (by folks that have used Roll20 for years).
As for free content that is behing a "gate", maybe you mean the D&D Basic Rules & the 5E SRD? I know at one time they were not distributed with the free license of FG, but that is no longer true, and hasn't been for some time.
I have no idea how much free content is available for Roll20 other than the 5E SRD and 5E Basic Rules. What else is there?
So now lets talk license cost comparisons.
Yes Roll 20 you can play and GM completely for free. In that use case, Roll20 is cheaper, no doubt, no argument. But, you have severe limitation on a free Roll20 account (storage size, feature access, sharing content between campaigns, etc) And content you buy can only be shred to ONE campaign. But you can play and GM no doubt.
So for $5/month on Roll20, you get more space, more features (dynamic line of site, ability to move character between campaigns), etc, and now you can share your purchased content to 3 campaigns.
For $10/month on Roll20 you get even more space and more features including the ability to customize and share your purchased content to 5 campaigns and move more than just characters between campaigns.
Now, on FG, for $4/month or $39 one-time you get a license that has no feature limitations (you can share your purchased content in an unlimited number of campaigns, you can customize the ruleset and most anything else. The only limit is that if you host/run a game, all your players also need a standard or ultimate license.
For $10/month or $149 you can get a Ultimate license, and now their are no license requirements on any of your players. They can all play for free.
So, if you are going to spend money on a license, either the Plus, Pro, Standard or Ultimate; FG is the same price or cheaper after 10 months.
Now, let's look at "content", using the D&D 5E books as an example:
The Player's Handbook
$30 on Roll 20 and you can only share it in 1, 3, or 5 campaigns
$30 on FG and no limit to the number of campaigns you can share it in
MToF
$50 on Roll 20 (and you have a share limits)
$30 on FG, no share limit
PotA
$50 on Roll20 ...
$30 on FG
Xanathar's
$30 on Roll20 but you can use it in the Charactermancer
$30 on FG (no such issue)
Say you want all the core books, they are 15% off on FG, no bundle discount on Roll20. Want to wait for a sale? FG regularly (weekly) has sales plus big discounts for the 2 annual Steam sales. Roll20? They don't believe in sales so no point in waiting.
So yea, their are use cases where Roll20 is cheaper or free, but I think the use case for most people is FG is cheaper. But, blanket statements are just misinformation. People should put together their own use cases and see.
'Our group of 4 people is going to buy x, y, and z and play for 1 year'
'I'm going to DM 6 different campaigns over the next 3 years and will buy all the books.'
Give people real info and not out dated "facts" and biased opinions and let them make an informed decision.
Opinion: That's a lot of money to spend on something that still doesn't work as well or as quickly as paper and pencil and a webcam.
An opinion that is absolutely valid. But it is your opinion, and one I do not share. My experience using FG, Roll20, Skype w/ Webcam and in person differs drastically.
Taking almost an identical group of players, with different D&D campaigns, in a typical 4 hours session, we would expect the following;
FG - 3 combats plus 2 roleplaying encounters
Roll20 - 2 combats plus 1 roleplaying encounters
Skype - 1 combat plus 1-2 roleplaying encounters
In Person - 2 combats plus 2 roleplaying encounters
If you are familiar with FG, and understand how to use the combat tracker, effects and PC actions, so much of the book keeping is take care of for you that combat is a fast, really fast. The system does the math (and we are engineers and math teachers and scientists, we are good at math) so we don't have to. It rolls saves and applies half damage automatically or no damage as needed. It considers prone, and cover, and mage armor. It doesn't automate everything, but it cuts out 80% of the book keeping that adds nothing to the enjoyment of the game.
But, it does not replace the face-to-face and human interaction of playing in person, unless you are using it in person (which I often do). VTTs are not for everyone, but they are far from an inferior experience unless you have decided they are.