You just have to do the math on it. If buying the bull barrel separately saves you money go for it. A stainless bull barrel will run you about $150. If the difference between the cheap model and a target model at your local gun store is more than $150, just but the target model.
A cheap model is about $250, plus $150 for the barrel, plus $100 for your stock. And you're up to $500.
You need to think about your sights. If you want to run the stock sites that's fine, but you're probably going to want an optic of some sort. So $50-150 for that. Though, scopes can cost way more than that.
Extra magazines? Large capacity ones are out of stock everywhere right now. But the standard 10 rounders are at least $15 a piece depending on where you buy them. So you should consider that as well.
And drop in trigger assemblies are run from $150 up to $400.
So the short answer is yes, you should be able to get the rifle with a bull already or separate one and the stock you want for less than $700. But you can easily spend $1000 making a good 10/22 target gun.