Right, it is HELPFUL, but look at it this way:
The average level 5 treasure (this is using the tables on Page 300 of RC Appendix 2) will consist of the following
1. 90 GP
2. 62.5 GP worth of gems
3. 50 GP worth of art
4. 4800 GP worth of magic items
This makes the ratio 4.2% of all treasure is money, 95.8% is magic. A level 5 magic item is worth 1000GP, so you would have to find FIVE level 5 treasure troves to reach the value of one level 5 item. This equates to being able to construct two at-level items per level, or purchase a bit less, on average. Either way, the vast bulk of all items will come from finds, not purchase or enchantment. If the party disenchanted, on average, half their finds (all the common items by RC rules) they would be able to convert that into the enchanting of 2 more level 5 common items, or possibly the purchase of one level 6 item. Naturally all this assumes the PCs have ZERO other expenses, and both rituals and consumables will be competing for that cash.
One can easily see that NOW AND THEN a party might sell/disenchant and then purchase/enchant something, and they might enchant an item now and then from cash income, but the game is pretty restrictive about this kind of thing! By design there are few items to be purchased or made, and many out there to be found. Selling will be reasonably common, but generally a level 5 party would be parting with items of levels 1-4. A level 4 item will only bring 168GP, useful if you have no reason to keep the item around, but only a modest source of income.
I'd also note that in RC's system rarity means PCs can NEVER purchase/enchant anything but a very very limited repertoire of items (basically vanilla items and a very few low power items of other types, generic stuff). A generous GM might allow for ways to create more interesting items at times, but by RAW they can only be found or possibly made by very specialized and rare NPCs. All things considered purchase/enchantment basically, at least in RC rules, are a stopgap that allows a PC to be equipped with a vanilla version of a necessary weapon, implement, armor, or neck item, required to meet basic bonus expectations for their level. I'd think that any GMs still running 4e at this point are using inherent bonus anyway, so even that is fairly questionable. Your characters are probably just as well off using their cash to throw drinking parties and horde ritual components.