Nah, the problem is getting the whole cavity set up to actually work. You can get a 20W pump for a couple hundred bucks.
The 'value' in a DPSS laser is more the time it takes to get the whole thing set up and working on a consistent basis. You can probably get the KTP, YAG (or nd:yvo4) and pump to make a laser that will do several watts of green for under $1000 on ebay. But you'll spend hours upon hours getting everything aligned and lasing.