Approach a local specialist garage who will likely be struggling with sales and come to an agreement for hire, you might have to arrange your own insurance and european breakdown cover but this shouldnt eat the budget too much.
You should be able to get something quite a bit better than an SLK which is a pretty common sight on the roads. In spite of the inclusive insurance, mileage loading and breakdown cover a grand to hire a 30 grand car for a week sounds ridiculous.
Surely everythings relative; a few years ago at a time when I was between cars I hired a Yaris for £15 a day. The car had 1000 miles on the clock when I picked it up, and I put 250 more on it in the 24 hour hire period. I know it was only a Yaris but it was still a £10k car.