@Angelica127
I host a lot of long-term guests so.....based on my personal experience and what I've read from your post........my impression is that the host was initially excited about the possibility of a large payout but once he calmed down and looked at the numbers found out after factoring in the costs, he would not be making much of a profit. Maybe even losing money.
Also, there is risk for hosts where guests gaining tenancy rights for stays longer than a month and long-term hosting is very different from short-term hosting because long-term stays are not short visits but rather guests are "living" in the home so more cooking, wear-and-tear, possibility of bringing friends/family into home are high - maybe the host decided he could not accomodate what would be needed for a long-term stay.
You say "only 20%" but 20% for a 3 night stay and 20% for a 3 month stay are totally different - I am sure the host was not expecting one of the first few bookings to be for a 3 month stay (meaning out of 90 days, a 20% discount will mean the host has to provide 18 days for free!!!) Newer hosts offer a special discount to the first few guests in order to get positive reviews. If someone were to stay 3 months, that goes against the purpose of offering a discount to the first few stays 🙂
To be totally fair, I actually have a 20% monthly discount set up BUT I adjust my nightly rates so that the monthly total payout meets what I feel I should make for long-term stays. Therefore, shorter stays in my home can seem a little bit more expensive that other competing listings - which is exactly what I was aiming for! (majority of my guests stay anywhere from 1 to 4 months)
I do think the host was wrong send an offer only to block the days like that and then open them up again. He could have just been honest about everything. In any case, I think it is better that your booking did not go thru because if the host had realized all of this later, he might have asked for more money or he'd have a grudge and could easily resent having you as a guest, or just cancel on you last minute. Imo, it's better for you to find a place where your presence and business is appreciated.
Good luck~ I am sure there will be somewhere that will be just right for you~!