Owning property in Canada is not itself a problem. Extended absences from the United States can be, because permanent residence carries an expectation of residing there and prolonged time abroad can raise questions about abandonment.
Residence is about where you live
Hypothetical example: a Hampton family intend to keep their house, spend summers in New Brunswick and have the children finish school there while the investor commutes. Conditional permanent residence is still permanent residence, and it is granted to people who intend to live in the United States. Keeping a Canadian property, bank accounts or family ties is ordinary and unobjectionable. Long or repeated absences are the risk, and the analysis looks at the pattern rather than any single trip. Families in this position should take advice on what their intended travel actually looks like before filing, consider what documentation supports continued residence, and be realistic about whether the plan they want is compatible with the status they are applying for.
Government filing fees for the immigrant petition, the residence application for each family member, and the later petition to remove conditions, all listed in the USCIS fee schedule; plus regional-center administrative fees, legal, accounting and translation costs.