Remy, I do not know if it is the same in your country as it is here in Ontario but here, once you are moved in the lot rent can only go up 1.2% a year. UNLESS the landlord can claim they made improvements, but must submit to the rent board first with an estimate. We are facing this in our park, they are improving water main and road repair, estimates should be that we are going up about $50 a month.
I know of one nearby park where a new owner came in and jacked the rent up for anyone new coming into the park with rents increasing from approx $350 to $625 and while this does not affect the old tenants who are still under the 1.2% per year it makes it almost impossible for them to sell unless they reduce their asking price drastically.
Also some parks increase rent for any newcomer by $50 a month, a little more reasonable.
Something to consider before you buy, not after.