Ok, just so we get the numbers right, lol, we are talking about the Sennheiser HD 2 0 1 (not 210!) Studio.
Furthermore, they will probably break in the period you mention, especially if you use them on the road for DJ-ing as well.
Having said that, they cost about a third of your original budget. So let’s say the 100 USD headphones need to last you 2-3 years, if you buy the 201s, you can buy three, in which case each has to last only 8-12 months (which I am sure they will).
Do a search on HD-201, there are quite a few posts on the subject, including someone (I think Terry) telling about the weak points in the construction.