I'd like to contribute as well to this thread, cause, I get asked by people if they should get a DMR.
I currently run a Sniper set up that I break out occasionally. This set up consists of a Real Sword SVD I had purchased for $1250.00 a few years back, before the opening of the borders for Airsoft and when these things were still quite rare even in Asia. I upgraded the brass 690mm 6.03 barrel to a stainless steel 705mm 6.02 barrel, which cost an additional 70 dollars or so.
Despite spending over 1300 dollars on a rifle I can not use this at every game. Some of the DMR rules in Ontario call for a bolt action only rifle to be used as a DMR. The SVD is a semi-auto only rifle so it immediately is disqualified right there. Some games will allow semi auto only rifles with a higher FPS, but ask that you contact the host. The two reasons the SVD will be approved is because A) It is a DMR in terms of real life applications and B) the size of it is so unwieldily it is quite difficult to imagine me using it as a standard assault rifle
Granted I can actually bring this rifle out to a game I usually end up playing one of two ways. I sometimes go out with someone else, do a two man sniper team(Me with the rifle, the other with a standard AEG). This is usually much slower paced and honestly quite boring. What happens a majority of the time is I stay with my section to be used as a DMR. What this means is while everyone is in a firefight I am usually a little bit behind the main fighting line trying to sling BB's accurately to peg people while they are fighting others. I'm never up front making the decisive plays, or taking the fight to the enemy.
Furthermore my BB's don't hit exactly where my crosshairs are placed. They do, at a very specific distance, but because we have Airsoft physics to toy with I have to try and set up my rifle optimally. This usually means I am sightly overhopping my BB's to get extra range; I put more backspin than necessary making the BB fly in a parabolic arc as opposed to a straight line. This gives me a bit more range, but requires me to start having intimate knowledge of my scope and my rifles capabilities, which I still don't have perfected after years of playing with the thing. This forces me to do follow up shots to properly adjust and compensate.
If there is a significant amount of wind I pretty much can't play as I can no longer make any shots at all... Period.
So lets recap real fast. I spent 1300 dollars on a rifle I can't use at every game, that to get the most range out of it (the point of a sniper rifle) I had to sacrifice precision (A much more important part of a sniper rifle), and I have to sit back and not experience intense firefights the same way the guys up front did meaning I have less fun overall. And even then, with all this, some games I still put it away and pull out a rifle because the situation does not suit a DMR at all.
If I were to offer someone a suggestion? Don't touch a sniper platform until you are ready. To get one tuned properly you will approach the 1000 dollar price point easily... Instead go on the classifieds, find someone selling a super tweaked, highly tuned AEG they are selling for like 700 bucks and go with that. You will enjoy your time more.