Ok, I've read through the pinned links. Didn't realize I was asking for a case study, so here are the numbers:
Market Value: $230,000 (zillow says $263k, which I think is way too high based on comps and tax value)
Original Purchase price: $164,000 in 2009
Original Mortgage Amount: $138,300 (this reflects a refi from 2013ish)
Interest Rate: 3.5%
Mortgage Term: 25 years
Term remaining: 18 years
Amount remaining on mortgage: $110,000
Gross Rents: $1500/mo x 12 x 0.1 = $16,500/yr
Principal and Interest: $693 x 12 = $8316/yr
Taxes and Insurance: $208 x 12 + 120 = $2496/yr
HOA costs: $288 x 12 = $3456/yr
Deferred maintenance notes: None. I have been proactive about maintenance. Biggest unknown is the refrigerator because I don't know how old it is.
Anything else special or unique: I have a HELOC for a bathroom renovation and that has a minimum payment of $77/mo. I make an additional $300/mo principal payment so I can pay off the bathroom within the fixed rate period. I will pay this off in January 2023.
Here's the long version of my logic train. Feel free to throw wrenches, that's why I'm here!
Renting in the new city seems to make the most sense for the short term (12 months), mainly due to the housing market. Not much to buy right now... but I could probably get a better price on a home, so I'm willing and at least somewhat interested in considering purchasing as an option. I have a free place to stay until the fall, so depending on the time frame there may be an opportunity to jump in and take advantage of these ridiculously good interest rates.
In terms of downpayment on buying a second home, I could theoretically access the rest of my HELOC balance for a downpayment - roughly $15k. I have about $10k in savings too, but that includes my emergency fund so I'm not super interested in tapping into that. I'd be looking at a purchase price of $100k (for a fixer-upper) to $180k, so probably the min loan amount would be $140k depending.
This is why I think selling needs to be on the table. I have somewhere in the range of $80,000 - $140,00 in equity (depending on which source you believe for market value). If I sold here, I could likely buy a house and likely have it payed off in less than 10 years (with the caveat that I'm not sure how long I'll stay there, but probably 2-4 years). I realize that I'd need to stay in the new city for 5 years in order to avoid capital gains taxes, but the prospect of being debt free in that short amount of time is appealing, and it makes all future decisions about location and employment much easier to make.
As for keeping the condo, I think the market will only go up. I've been averaging about a 4% increase in value per year, and I'm up conservatively up 40% over the 10 years I've owned it. There is nothing that makes me thing this will stop. It could slow or drop a bit during a recession (including the current one), but long term its easy to predict a strong net upward trajectory. A house/condo in the new city would not appreciate at that rate. Also, the spreadsheet I found gave me a total ROI of anywhere from 3% if you include the HELOC payments to about 20% if you don't.