i spilled a sodie on my keyboard, rinsed it in the sink and left it outside in the sun and it evaporated. I don't know if this strategy will work for you. it's also 110+ degrees (F) ymmv

you can buy a used one on
e
b
a
y


for a couple hundred USD

theres also atleast one that i seen that could be used for parts for under 200usd
all of which, is alot less than 600euro
the place you took it too sounds like a complete scam