@Nicholas DuLong you're very welcome. As you and I mentioned, it's normal for investors and agents to have different perspectives given our very different "roles" and objectives. Also, nobody has a crystal bowl.
When it comes to Tulum real estate, there's the bust camp and then there's the "other camp". I'm calling it the "other"camp because I don't know if we should call it the "boom camp" or merely the "no bust" camp or maybe the "neither bust nor boom camp".
In think that both cases have already been laid out in this thread so I'm going to focus on your reasoning and question, as well as a more qualitative perspective.
You start in the bust camp and then you're talking about buying there because you seem to think the bust is going to be followed by a boom I was stunned by the reversal. Two questions to ask yourself:
1. If you're right about that, why don't you wait for the bust to happen to buy? You'll get a better price and you'll take less risks.
2. Why would that sequence happen? It makes no sense to me. If the bust is caused by a huge oversupply of properties, that oversupply has to disappear to solve the bust. How's that going to happen is the question.
What you need to do is figure out how big the oversupply is and how much increase in tourism will be needed overt the next 10 years to absorb it. I have figured that out for myself but you it's not going to have the same effect on you unless you do your own calculation. That's just to absorb the supply and you'll need even more growth to create a boom!
You also have to ask yourself why would all those people go to Tulum, when what made Tulum special and attractive has disappeared. The early Tulum lovers have moved on to other places, where the municipality doesn't deliver building permits to anyone and their mother. When I was traveling through Mexico last year the expression I heard most from the mouth of real estate professionals is "We don't want to become another Tulum". As a result, permitting is being restricted so that's where the supply/demand imbalance is going to increase in values. Do you really think people will go to Mexico to find themselves into another condo jungle?
Do you think there's gonna be enough beach space for all these people if there's gonna be enough of them to fill all these properties? How much more do you gonna have to pay to get into a beach club after hopefully getting a parking space? Traffic jams, overcrowded areas. Do you think it'd look like anything you saw? Also, do you know how much sargassum is going to cover the beach in 10 years? We've hardly had a winter here in Canada so I'm not sure that the culprits, believed to be global warming and pollution, are receding any time soon.
If you buy for lifestyle, it's another story in that you could cover your costs. I'm not sure about your travel, as it'd depend on the frequency and price of it. The question though is whether you'll like the lifestyle there, in relation to my comments above. Be careful what you wish for. Also, I'm not sure staying one week for the first time would let you determine that but you know better.
But then, as you suggest yourself, there's gonna be plenty of empty properties generating little rental income. In that kind of a scenario, Wouldn't you want to be the guest, not the host or the renter, not the owner? Your holidays would be much cheaper, you'd stay in different places (more variety) and you could stay in much nicer places for the same budget.
I understand the reason you'd want to buy is to be able to capture a potential capital gain. But where is the increase in value going to come from? It's a beach town market. There are so many second homes and then, when it comes to rental properties, no occupancy = no value.
An investment is about numbers. Make sure that your judgement isn't clouded by "My family and I just returned from a lovely week in Tulum." I'm not sure you want to be one of the many who went there, bought impulsively and regretted it after and can't sell without taking a loss. Maybe you should let time pass a bit and the fever retreat and the right decision might become obvious to you.
If you do decide to buy, yes, you'd need to be as competition proof as possible (which will probably mean paying and rising more). Bear in mind though that inferior properties renting for close to nothing because they're empty will still be competition.
Hope this helps!