edit: not aimed at u wasabita
i am afraid u got a wee bit wrong.
u don't get more money either way. let's take the rates posted by tenchu.
when the bank (or if its a financial institute or exchange bureau) buys USD from you, you will get 33.3456 TBH for every one (1) USD they r buying from u.
when they bank sells USD to you, you will have to pay 33.6911 TBH for each USD you buy.
I fail to see how u get more money either way. now, in some countries there is better competition among "currency exchanging companies", which usually gives u better rates compared to currency exchanging companies" in other countries. that's why it might be better to exchange money in for instance ghana then in peru. but that says nothing of it being better to buy or sell. think of it more as an exchange, hence "foreign exchange", "forex", or "FX". on very rudimentary way of comparing exchage rates between different banks is to look at the "spread", the difference between "buy" and "sell". the bigger spread is, the worse rate for u as a customer. this can be done even with different base currency, however, remember to re-calculate!
more on forex
any future replies by me in this thread will be done as updates in this post since i don't want to put this post on the first page every time i am answering in it.
firebird>>
because u have two (2) rates, one for sell and one for buy. wasabita brought up one of them, if u want to do the opposite, which u r referring to, u have to look at the other rate, which will be different. therefore u can't make the assumption u did.
example: wasabita sold yen, lets call this the sell rate. this means that if u want to buy yen, u will exchange money according to the buy rate, which is not the same as the sell rate. note "spread". only top-traders gets to trade at a practical "no-spread" rate.
wasabita>>
a man of many trades i see