What garli said. “We haven’t decided on a ring yet” (truth) “and since I’m watching our expenditures” (also truth) “we’re going to make sure we get the best bang for our bucks” (which would be zero paid, in this case). Just make sure your “prospective groom” is in on it, if you post a photo; nobody likes getting that call from parents or friends that starts, “SO! Who’s the lucky lady?!” and then having to explain.
Plus it would make a great series, IMHO.