Solid/affordable sniper, that isn't a piece of crap = Classic Army (CA) M24. Comes in around $350 - $400. Worth while sniper rifles go up in price from there and all will likely need some upgrading/modification.
Grab a G&G M4 as an ol' reliable backup at around $200.
Before going all sniper, read this;
ďREALITY IS LIKE A STONE. TO MANY ITíS HARD AND COLD, THEY CANíT HUG IT OR EAT IT, IT ONLY FRUSTERATES THEM AND DOESNíT DO THEM MUCH GOOD. TO OTHERS ITíS STRONG AND DEPENDABLE, YOU CAN BUILD WITH IT, BUILD UPON IT, OR WORK WITH IT, ALSO USE IT TO SMASH PEOPLE IN THE FACE.Ē