I'm surprised no one has mentioned a 1909 Argentine (marked "Berlin") Mauser. Many wonderful custom guns have been built up on this action, and many have been rebarreled to 30-06. You can get into one for ~$400 in good condition with basic wood... use the budget balance to upgrade the stock.
Here is an example of one.
https://www.gunbroker.com/item/838073328 If the bore is good (ask the seller), probably the first two things I would do is shorten and recrown the barrel and install some medium height base-and-rings with a decent scope. If it shoots to your liking, put the next dollar into a blue job and start shopping for a stock.
One reason that no one may have suggested the 1909 is that the OP's post made it sound like he wanted a turn key .30-06 Mauser. Responses were geared toward that assumption.
If the OP would have indicated that he wanted to BUILD a custom Mauser, I might have suggested a 1909 depending on his budget.
I would never recommend an inexperienced Mauser aficionado buy a sporterized Mauser to start their custom build on. Why? because all too often, they are not correctly drilled and tapped. Hole placement can be off, they can be off center or canted. A novice would not typically know how to correctly identify if these modifications were performed correctly and can trip up even more experienced owners if they are not diligent. In fact, this example you provide does a wonderful job of illustrating this danger. The scope base holes on the front ring are located too far back. The rear hole is drilled through the lug web or worse, through the face of the lug seat. A buyer would be pissing away $329 on this one and others similarly modified. Buyer beware!
Generally, much better for a prospective first time Mauser owner to buy an unmolested Commercial Mauser or an unmolested Milsurp action if they plan on commissioning a custom rifle. Too easy to get misled by the promise of savings "because most of the work has already been done" when all too often that work was done incorrectly.
A nice custom rifle built by a reputable builder can be a good alternative and often a bargain if the styling suits your tastes.
