Youre on fire today mate :-)
Check out Stansted to Plovdiv on Ryanair. Plovdiv is a similar distance as Sofia to Bankso and there are 3 return flights a week starting around 35quid each way. Plovdiv is also a really cool little city and home to quite a growing nomad community. Hope this helps :-)
PS One of your posts mentioned future visa issues for your better half. Google. Surindar Singh. Was going to mention it before but when you mentioned your e residency and bulgaria, it reminded me. Would need to be quick though ! But would save a small fortune.