Try Etap Hotel group, they have recently opened a brand new hotel in Cardiff City Centre and are very cheap, Ive heard from a friend who has booked recently for GP weekend at £32 per night and I think that may be per room
http://www.etaphotel.com/etaphotel/ficheho...che_hotel.shtml
Paradise Park is an excellent attraction in its own right, we visited there this summer and had a great day, the addition of the Speedway museum will make it a 'must visit' next time we are in the area next spring. the Park alone is a full day out and is one of the most well laid out animal parks in the country
Tickets are always available on the day at the stadium office........the chances of a sellout are unlikely, more likely to be the the sub vendor of SGP tickets has sold their quota.