As I'm not an expert in Garand appraisal, it's a hard question to answer. CMP Garands are available for less than $1000, and in fairly good condition. The problem is the IH receiver. As these aren't available from CMP at the present time, the question really centers on the condition of the particular IH Garand that's available for $1000.
I'm sure many would say that's too high a price. I don't think so, provided you aren't going to have to replace a bunch of parts to get it to shoot well. Parts that used to be cheap are no longer available for bargain prices. Op rods, for example, are a couple of hundred dollars, I believe. Rebarreling isn't cheap, either. So, if it needs major work, that $1000 rifle can turn into $1800 easily.
Just a crazy idea. You might email some of the Garand builders and see if they have any they have built from IH receivers. The prices are higher, like around $1000 to start, but you will generally get a guarantee.
Garand Guy
You can see from this site that a "Super Premium Grade" is available for $995, with a 1-year warranty. This includes a new barrel and a new stock. If you're willing to wait, this builder may be willing to sell you a IH when he gets one as a trade-in, after he rebuilds it.