For accommodation check out the
Christchurch Hotels page.
Since you mention that you are looking for a cheaper option i would suggest the ITuscana Motor Lodge
'If you’re looking for a good value among the hotels in Christchurch, the centrally-located Tuscana Motor Lodge at 74 Bealey Avenue is surely worth considering. Hagley Park is just a block away, and you can easily walk to a myriad of city center attractions'
I hope this helps.