Currently buy from musicdirect and have only bought 180g and 200g.While most of those "audiophile grade" pressings are very good, I think you will be very surprised how well a good condition, clean old original pressing can sound. I have a mix bag of new pressings and older stuff, and many of by best sounding albums are used pieces I picked up cheap from local record stores.
Another way you might want to give your collection a nice jump start is looking for lot sales, both here on the gon and ebay. Many go for about $1 or less a record when purchased in a lot.
While I pick up hard to find items online, I find that digging through old albums is one of the best parts of the hobby.
Happy listening!