DeadBase Installments

I have a copy of DeadBase IX that I reference quite often. It's truly a great resource - often quicker to flip open and find my answer to questions/curiosity than it is to search it online - and it's just fun to see setlist, venues, reviews, etc. all in one, organized, physical place.

I'm curious how much variation there was year to year. Is it worth picking up an older version? I see some from the 80s on eBay for reasonable prices. Or, if I was willing to spend $100+ is DeadBase X that much of an upgrade from what I have now?

Thanks!