You may want to specify if you are looking at the "sportline" or "proline" version, The sportline versions are normally around $150-$190, and have cheaper external parts; Bodies, stocks, grips, ect... However cheaper doesn't imply that they are low quality.
I have owned a sportline MP5 for almost a year and use it regularly for plinking. I have never had any issues with it, internally or externally. I personally recommend any of classic army's sportline MP5 models, and their FPS is just the right speed for AzCQB (
http://www.cqbazairsoft.com) A great field you can find on the I-10 and Warner Rd. Gearbox Airsoft carries Classic Army Sportline models,it would be well worth a trip to head down there and check out the model your thinking of buying!
Best of luck with your hunt
