Check out this website.
http://www.venere.com/belgium/brussels/#p|1;f|venere_ranking-t|all-z|all_areas-r|r6-c|all_rate

You can filter by price and location.

Read the reviews by people who've stayed there before. They'll tell you if there are clean issues or not.

You certainly should find something less expensive than Novotel.

http://www.hotel-mozart.be/

you might try the Mozart...clean, a bit on the funky side, but good value, and a seemingly nice clientel (many return guests)..excellent mid-town location. We found the walk to Central Station to be an easy one, too. You can see Grand Place from the hotel...

Stayed at the Ibis in the Ste. Catherine area 2 weeks ago which is just about 2 blocks from the Ibis you mentioned. Walked there from Central Train Station. Price was $79.00 a night. Room was typically small European type and the bathroom was abolutely TINY. However, great value for the price, safe area, front desk very helpfull, walk to the areas you mentioned and it was squeaky clean. It is in the area of the "old" fish market so if you like seafood there are lots of good seafood restaurants nearby. Hotel is next door to St. Catherine's church

http://apartmentsinbrussels.be

This one looks quite new and bright unlike many places in Brussels. BTW. Certain areas of Brussels is to avoid for tourists. The area around north station, north and northeast of brussels not so nice to stay. If the price is low look for a possible catch. If the price is good then verify that it's a good location.

Right next to the Ibis and Novotel Hotels at Cetral station, is a Best Western hotel - Carrefour de L'Europe. We stayed there 2 years ago and were very pleased with the Hotel, as well as its location. We had a room with a view on the small "Grasmarktplein" and it was lovely.

Stayed at the Scandic Grand Place last year for two nights and agree with most of the comments on Trip Advisor -

http://www.tripadvisor.com.au/Hotel_Review-g188644-d229566-Reviews-Scandic_Hotel_Grand_Place-Brussels.html

pros - reasonable rates, very well located (between Central Station and the Grand Place), very good breakfast, helpful staff, mix of business and tourist clientele; con - standard rooms looking into the atrium likely to be a bit stuffy with more than one occupant.

We lovesd our stay at the Hotel Welcome. The have some special summer rates starting around 70 Euro. It is well located and the metro stops right outside the front door if you want to go farther afield http://www.hotelwelcome.com/gb/prices.html