Reason for loan is - Buying something for bitcoins
Buying what? Digital goods, or physical goods in shops?
hexcoin offered you 0.015BTC and that is reasonable already since your account is still Jr Member.
Even if you account is with Member rank, the loan you are asking is still high.
Its like you are selling your account.
Nope, if the account is at Member rank then it is already worth 0.02-0.04 depending on activity. A medium to high ranked Member account is enough to cover that. Also, a Sr. Member account or above could lend this amount even without collateral, because if he/she defaults, the account's value will drop by more than that.