Upgraded X-over for Buchardt S400?

I heard the upgraded versions these speakers, with I think Dueland wiring and much better caps, and was blown away with them.  I bought the stock S400 speaker and am really enjoying them, but wonder if there is an affordable upgrade for them.  I contacted Mads and he said the upgrades network would cost $1K, which is out of my budget.  Does anyone have experience with X-over upgrades for the speaker?   Thanks. 
Whitestix, a good buddy of mine has the S300 and it’s pretty stunning what those relatively small speakers can do. Haven’t heard the S400’s except at Axpona a couple of years ago but I couldn’t get a real feel for them there. That being said I have had Danny Richie with GR Research upgrade the crossovers for two pairs of speakers I own. He does fantastic work and is responsible for the crossover designs in many speakers. You may shoot him an email and see if he has any offerings for the 400. I have a pair of peachtree d5’s that he upgraded which cost around $500 for new crossovers and level matching the tweeters. Same with a pair of Era D10’s. Good luck.