The Doepfer DIY Kit is a great starting point if you can make a case for it; this was the most cost-effective option for me when starting out in Eurorack.
I began by making a cardboard case with two of the four rails supplied. As my collection of modules has grown, I've built a 6U, 84hp case with 12mm plywood. For my needs, at home, this is perfect. As time goes on, I'll probably make a hardwood case that's a fancier.
Several of the modules I own are heavy on power consumption, but the Doepfer DIY Kit has no problem accommodating them. When I want to expand into another case (it's inevitable!), I'll buy another of these; they're excellent value for money.
Service from Thomann was excellent as usual.