This is governed by ‘pragmatics’, the knowledge and interest you and your hearers or readers bring to the situation, rather than abstract grammar.
If you were speaking of qualities of the properties which endure into the present, you may use the present tense:
I bought a new coat last fall. It is orange and has a hood. If you find it, please let me know.
All properties were sold on 25th May, 2011. They consist of a .25-acre lot with a 2-bedroom house and an adjacent .25-acre lot where the new owners are now putting in an elaborate garden.
But you are not required to use the present. You do so only if your topic, the matter you are talking about, involves the current status of the properties. If on the other hand your topic is the status at the time of the sale or the transaction itself, you use the past.
I bought a new coat last fall. It was orange and had a hood, and it kept me warm all winter.
All properties were sold on 25th May, 2011. They consisted of a .25-acre lot with a 2-bedroom house and an adjacent .25-acre lot, at that time undeveloped. The proceeds were used to pay off the estate taxes.
When it comes to the price, you are almost obliged to use the past tense: The price was $500,000. Markets change rapidly, so the price is in most circumstances a quality of the transaction, not the properties. If you say the price is $500,000, your hearers will infer that the properties are now being offered for sale again at an asking price of $500,000.