Dang it, how could we have missed that. The treasure's the most important bit, if you believe some players!
How about modifying the spider's treasure a bit?
1/10 coins; 1/10 goods (gems only); no items
The original monster had OK treasure:
AD&D: Types O, P, R in lair
BD&D (AC9): Types J, K, L.
Type O:
1-4 1,000s of copper pieces: 25%
1-3 1,000s of silver pieces: 20%
Type P:
1-6 1,000s of silver pieces: 30%
1-2 1,000s of electrum pieces: 25%
Type R:
2-8 1,000s of gold pieces: 40%
10-60 100s of platinum pieces: 50%
4-32 gems: 55%
1-12 jewelry: 45%
Type J:
3-24 copper pieces per individual
Type K:
3-18 silver pieces per individual
Type L:
2-12 electrum pieces per individual
So I'm thinking one of the following:
Treasure #1: Double coins, standard goods (gems and jewelery only), no items
Treasure #2: Standard coins, standard goods (gems and jewelery only), no items
#1 seems a better fit.