The centre-back is out of contract at the end of the season with reports this week suggesting he is primed to sign a pre-contract agreement with an English Championship club.
As well as being able to contribute on the field in the short-term, the Falkirk coach reckons he has the potential to make them a tidy profit in the transfer window down the line.
"I think he would be a fantastic signing for either of the Old Firm based on the value for money it would bring,” Miller told Go Radio’s Football Show.
"And if he's really successful at one of these clubs for 18 months or two years then there are opportunities to sell him on down the road.
"You think about what John Souttar would be worth if he still had years on his contract.
"So the fact you can get him for a fraction of that allows you to boost his wages a little to compete with higher-end Championship teams.
"There's no doubt if John Souttar goes into Rangers or Celtic the profile goes up with the opportunity to show how good you are at a different level and in Europe.
"And it gives him a better chance to play for Scotland."