Take the standard UG (haftungsbeschränkt) if you don't have the capital. There the base capital requirement is 1 Euro. You can even found a GbR which is not a limitied liability company but serves quite well in most standard cases.
In any case, the number is not too low to guarantee compensation: The base capital of the company is public. Every business person in Germany knows that number. So if you're trading with a fresh GmbH you can safely assume that at least 25k were available at some point. Excluding plain fraud, you can be pretty sure that at least bills in a given range can be paid from that capital. You'd have a second look if they try to order something which goes beyond their base capital. Transparency requirements don't help much with fresh companies since there is now history to judge from.
