hi Melvin,
Good call on buying in that cheap. Here are my thoughts:
1- I agree with j Martin that the long term appreciation for Vallejo has some headwinds. Remember, when we have another regional correction Vallejo will be one of the first areas to go down, and will go lower than more central Bay Area cities.
2- having said that, we are now in an upward market, and I personally think it has at least a couple of years growth ahead. I know SF and peninsula are on fire due to tech, so the outer areas are getting priced out buyers. So no reason to sell/dump now.
3- how much value can you get from that lot? How about subdividing and building on it yourself? What is the upside? If it's decent, that may be your first flip. And then maybe sell off both in a year? If so, I'd definitely do a 1031 exchange into another investment prop (or flip if you want to do those.)
4- If you sell/1031 Vallejo you will have sizeable cash. I'd consider buying in better markets closer in. Yes you will need 30% down to cashflow, but you will be insulated better in bad markets. And future appreciation will be more solid on the peninsula. You could consider upcoming hoods in Oakland too. But bottom line, if you can buy/hold on peninsula or Oakland, you can make real money on future appreciation. Having $300-400k cash puts you in a position to do that.