You need to give whatever you can afford and feel comfortable with giving. I got married 10 years ago, some aunts/uncles gave me IRL£250 and some gave IRL£50. It made no difference to me whatsoever what was given, the fact that they shared in our special day was more than enough for me. If people feel a present is "cheap" I say shame on them and they need to look within themselves to see what is really cheap.
A bride and groom should not always expect the meal to be covered by the gift, sometimes expensive hotels are used with room rates of EUR180 or even EUR250 for one night, can a person on a pension be expected to give a EUR200 present and pay for their o/night? As I said give what you can afford and what you feel comfortable with and enjoy the day out. On a separate note, so much money is given nowadays (and 10 years ago I received a lot of money) it is often nice to receive a gift. Everytime I use certain glasses, cutlery set or vase I think of the person who gave it to me for my wedding day and sadly some of those persons have passed away but my memory of them is triggered everytime I use that special something.
Alternatively, you could give a smaller sum of money and a gift.