How old is too old when buying older clubs for cheap?

So I want to get hybrids because I cannot hit my 4 iron and I have a huge gap between my 5 iron and my 3 wood. When I take out my 4 iron I will have a 2+ club gap between them so I will remove an extra SW I have because I suck with that as well so I can put 2 hybrids in my bag. Now I have spent my share of money over the last couple months on golf so to keep my wife not yelling at me I wanted to find some as cheap as possible. So I find a couple on craigslist for $40 for both. With what appears to be the perfect lofts for my yardage gaps, 19 and 22 respectively. They are Adams A7 Idea. From my research these look to be about 7 years old. My question is has technology moved so far past these that they aren't even worth $40 for both. I really need to get hybrids but can't spend too much for them.

I've found similar deals for clubs about 2 years back.  But if you like those,$40 is a great price.  Hit them and see if they fill your yardage gap and they feel good.  If so, do you care how old they are?

I had the same need a couple years ago and paid $50 for two nice Callaway hybrids that were 2-3 years old. It was some of the best money I ever spent on equipment.

Caution: you don't get to test-hit clubs before you buy them from Craigslist.

Go to a large golf shop and look at their trade-in bin.  Sometimes you can find matching hybrids in there. Then, test-hit them to see if they fit your need.

+1 to the suggestion of test hitting clubs before you buy them.  Some people take to hybrids easily, others like I do not.  And not all of them feel the same or perform the same for each person.  You don't mention the shaft but I have become a true believer that the shaft makes the club in many ways because it can have such a profound impact on ball flight.

Well, don't think  that you will find any cavity back irons amongst the 'oldies''.  So cost should not be the most important criterion.