There is no such thing as a "low priced sniper" if you are serious about this sport...Sniping is probably the most expensive of all the roles as well as the most difficult to be effective at.
Your best bet is to get a quality AEG and be a Designated Marksman. If you want more info, PM me and I will be glad to help.
If none of that has dissuaded you, I have a sniper rifle I never use...again PM me.