Well, Outpost users are (for the most part) illiterate dumbfucks who are too stupid to act on their own without using a spreadsheet as a crutch, and anyone asking for more or less is a scammer. <--Pretty much a synopsis of trading these days....

Now, as for bp.tf (i'm quite active, mainly in the forums, havent done any suggesting as of late), BUT, there are a couple flaws with what you're saying.

--Only mods should be able to suggest prices..
>This would be detrimental for 3 reasons.
#1, Mods have final say. No matter what the votes say mods can accept/reject a suggestion, and this is a good thing, since a lot of people blindly vote based on a user (blue-star vs. white star), others will vote based on what they want to happen, and others will vote based if they see a bunch of links (even if they're not valid). So, if only mods could make suggestions, and only mods could accept them.....You could see how that would be a problem.

#2, It would be too difficult to keep every item up to date (as it is its already quite hard).
As it is, there are roughly 6000 unusuals (and a couple thousand other items?), so keeping items refreshed every 2 months would be quite challenging if only mods could make suggestions.

#3, It wouldn't be as community based, and would lead to issues like the spreadsheet faced. If only mods could make suggestions, than how is it any different than the spreadsheet? aside from the fact that control is in 10 hands vs. 1 (doesn't really make a difference at that level).

As for key suggestions, I assume you're mainly referring to long218 when you're talking about people making suggestions with 500+ keys. Now, i'm not going to go into the whole issue long with carders because frankly, its not important. BUT what is important is this, people accused him of manipulating prices because he had 1000~ keys. Now, he JUST bought/sold via paypal (never traded keys for refined), so increasing the Key:Ref ratio really only hurt him as it made it harder for him to trade other items for keys. But theres not way he was benefiting by keys ref value increasing since he never sold keys for ref.

Now, about the key suggestions themselves--While Outpost does NOT constitute all trading that occurs, it is a pretty big part of it, and really shouldn't be ignored. Keys would rise on their own with or without bp.tf, whether bptf speeds it up a bit or not is beside the point--because any price guide will have some impact on the market no matter what. BUT to say keys go up solely because of bptf is quite false. Keys began rising before bptf changed its price, and furthermore, recently there weren't any suggestions for about a week, yet plenty of people on Outpost were selling keys for 2 scrap more (quite easily). So the only downside to not keeping keys up-to-date is that the smaller newer trader loses out. The bigger traders will continue to raise prices, and others will follow, but the smaller trader will just take whatever bptf says. So ultimately not keeping the price up to date would just hurt the smaller trader.

Now is backpack.tf perfect? Most certainly not....
There is a lot of room for error, and imo, any unusual price guide is going to take a lot of heat for being inaccurate due to the nature of unusuals, but the majority of the recently updated unusual prices are pretty accurate (again, not all, but most).