When we negotiated the contract renewal, they wouldn't reduce the monthly fee but instead offered me to bring a second person at no extra cost. So we could share my 40-Euro-per-month membership, that is 20 Euro per month each.
The ISC is a decent but not a luxury gym. They have enough space, modern equipment and clean locker rooms, but they don't have spa/sauna and do not offer courses.
If you're interested, please write me with some contact detail, phone or email (I can't send many messages here). Since the contract already started I appreciate quick deciders.