just got some bitcoins and wanted to ask how i could trade for steam wallet at current value ?

if u know about stellars or got the bitcoins from there . There is one of their staff members on the forums who is giving 20$ steam wallets for 14$ atm... otherwise u can use this Clicky
I tried this site along time ago so it is confirmed that they deliver the code as fast as possible if there is problem u can just use the support or contact the owner via Steam

I bought 10 tf2 keys for 15$(1.5$ for a key) from a guy in steamtrades.com

You're probably not going to find many people that will sell you a wallet code for the exact price as most want to profit. Sometimes one will get lucky (i.e. last summer sale I bought 8 $20 wallet codes off Ebay for $16 each), but really to get the best bang for your BTC is to use your bitcoin and buy TF2 keys from a trader. There are tons of places to find a reputable trader that will sell you keys for bitcoin (Steamtrades, tf2-trader.com, etc) and you can get a really good rate if you look hard enough (1.60 - 2.00 per key). Right now, about 1.80 - $2 is an easily findable rate. Then take the keys, sell them on the market and you'll have a nice chunk of Steam wallet money. Or just use the keys in trades for games (save even more money that way).

If you have $30 in BTC, you can easily get around 15-17 keys depending on the rate you're paying, selling those on the market right now will get you about $2 per and thats after Valve fees, you'd actually be profiting by doing that and would have more than $30 Steam wallet.

And again, you can probably find whatever game you want cheaper from a trader for the keys than using Steam wallet to begin with.