You are supposed to give what you can afford and with a full heart.
My sister made two shidduchim. One was a very poor couple – he was Israeli, she was a russian immigrant. They bought her a beautiful necklace (around $100) and my sister cherished it. The other shidduch gave her around $1000 and she used it to go backpacking through Europe that summer.
Both were greatly appreciated by my sister, each in their own way.