I agree, Haymarket type facility is now becoming the norm.
However, a slight clarification. Vanderbilt does not have an AD, and have spent 1/10 of those linked while competing in conference with a third of (linked) them. Vandy was in the bottom of the toilet; think urinal cake, before Corbin showed up.
I don't know if it's the norm yet... probably a stretch.... but 5-6 years ago, Haymarket Park was one of the top two or three in the country. Some still think it's top 10:
http://www.mademan.com/mm/10-best-college-baseball-stadiums.html
Ohio State and Penn State both have very nice ballparks, so NU won't be alone in the Big Ten. But for the most part, the best stadiums and most improvements have been made with the non-northern climate schools -- not surprising. There are still very few northern schools that can compete with Nebraska so far as facilities are concerned.... most simply won't invest in their baseball programs that tend to attract little in the way of fan interest and revenue.