0.99 .com/.de Domains
I saw nessness' thread (https://www.lowendtalk.com/discussion/149237/com-domain-for-just-1-9-eur#latest) and checked for other offers. I stumbled across this offer. GoDaddy offers .com and .de domains for 0.99€ in the first year at the moment. It renews at 15.99€ which is quite pricey, but I guess you could transfer it to a cheaper company.