Pricing should be related to the unit economics of delivering the solution. Each of the different pricing options has its own set of assumptions around that, right? If you have a financial model, you should be able to sketch out each of the different options and see which one is more realistic.
For example, let's say it costs you $10k / month to operate (I am just making that up). You need 1,000 customers paying $10 / month just to break even. Part of that $10k is presumably some kind of variable advertising or other customer acquisition cost (CAC). What's your cost to acquire 1,000 customers? What's the average lifetime value (LTV) of a customer (which of course you don't know, but you'll have to take a stab at it). Cost of acquisition should be no more than 1/3 of lifetime value from what I understand.
What if the CAC portion of that $10k has only got you 500 customers so far? Maybe you need to increase your ad spend. Well, that just changed your monthly burn. So you have to factor that into the model. And you have to continue to update the model as you collect data. Because when you start out you have like a dozen customers and all of this is just speculation.
So if you are offering a free tier, that's basically marketing costs, right? You're trying bring enough people in so that some number of them convert to paid to make the unit economics make sense. Well, how many people is that? Are there enough of them? Can you get to them? How much does it cost you to do that?
Freemium only works well for products that either have a viral component, or the user comes to depend on them for personal data or storage (a la Evernote). If your real estate agents are going to be storing tours that they reuse over and over, and you set a limit for the free tier, maybe they are incentivized to upgrade.
I don't think the $1 thing makes any sense, and I haven't seen any products doing that (and I review a lot of SaaS products). It sounds like your intention is to reduce churn by erecting a small barrier at the point of sign-up. If you want to try a free tier, why don't you try looking at your engagement model more closely. Maybe there are features in that free tier that can help with referrals, reducing your CAC?
You're basically segmenting the market, or not, and assuming that some users will always be freebies, and some will be paid, or they are all the same. What's different about their behaviors in these supposed segments? If that segmentation doesn't exist, then you shouldn't try and split the market with freemium. Are there agents that only look for free tools, but will gab about it to their colleagues? If not, forget Freemium. Also, you can offer coupons to emulate free and see if your conversion of those folks to paid make offering a permanent free tier worth it.
That's what should drive your decisions, not these abstract notions of perceived value or not. (1) What is the market segment used to doing for products like this? (2) What do they pay to solve this problem with other solutions currently, and (3) if there is a segmentation around price, does the lower segment do something that inherently helps market to or convert into the higher segment. And (4) does the model work with which ever the answers are to these questions.
I honestly think that wrangling with pricing experiments with too much precision at this point is way too early. Just pick something that doesn't have you loosing money and start trying to sell it. You can always adjust it later if it's not too drastic.