Seeking 2 German (T-Mobile) prepaid sim cards

[snaimon]

Looking for 2 German prepaid SIM cards, preferably T-Mobile, standard size, but am willing to consider other providers.

In the past I have found USED cards plentiful on Ebay.de but don't see anything reasonable there. I have purchased 3 such cards and sold 2. This was several years ago.

I have found 900 coverage better than 1800 in the past -- the reason I would prefer T-Mobile.

The cards would be for my son and his wife traveling to Germany and other EU spots in the summer. We, too, are also traveling there this summer.

I used to have a SUNSIM card but they were bought out and then either went belly-up or the card expired, with credit.