1st editin has the following rule for additional exp. based on gold and gems:

Gold Pieces: Convert all metal and gems and jewelry to a total value in gold pieces. If the relative value of the monster(s) or guardian device fought equals or exceeds that of the party which took the treasure, experience is awarded on a 1 for 1 basis. If the guardian(s) was relatively weaker, award experience on a 5 g.p. to 4 x.P., 3 to 2,2 to 1,3 to 1, or even 4 or more to 1 basis according to the relative strengths. For example, if a 10th level magic-user takes 1,OOO g.p. from 10 kobolds, the relative strengths are about 20 to 1 in favor of the magic-user.

The 2E DMG seems to say it's 2xp per 1gp for rogues only, though I remember a table (maybe it was only in the first print of the 2E DMG which is a little different) that includes a 10gp to 1xp universal award. With the 1e system 100 kobolds would yield an average of 750+113-364 xp with a 50% chance for an average of 3,563xp of gems for lair treasure (30-300 kobolds). Using 2e rules and treasure, it's 700 plus 11-36xp for gold with an automatic average 356xp for lair treasure (assuming 1st level or maybe half that for gold since kobolds are 1/2HD).

100 1e kobolds: 750+239+1,782 lair (at a 1-1 ratio)=2,770 avg. (990 w/out lair)

100 2e kobolds: 700+24 +356=1,080 or 4,284 for Rogues (724 and 1,180 without lair).

So, the 2xp per gp for rogues only is obviously stupid. Also, I think that in general that 2e awards more experience outside of gold, but not by enough to approach the 10-1 versus 1-1 difference. Playing 1e, my experience was roughly 50% gold, 50% monsters and treasures combined. I think I initially used 1-1 xp-gp as a 2e DM which was a mistake since treasures in 2e are noticeably bigger, while the exp awards for monsters are only slightly higher. 100 2e kobolds: