If you are looking to create a place which can act as payment medium with no expense to increase the prices then it may not do the job,more people will come to spend or sell their coins for now which make the prices to go lower.But having such market place will really increase the use of cryptos for the paymet system.
When a marketplace is attractive enough (in terms of easiness and convenient) then it will get more users for spending cryptos but it does not mean it will help to prices to go lower but it will enable more people to adopt cryptos for the reason of using such a marketplace. Similarly I believe, building a great marketplace in the times of crisis is not a big issue but it may not attract more new users how it would suppose to be performing in the times of rising market conditions.
Condition of overall market scenario is more important for the success of any business because sailing on opposite current is more difficult for anyone. A positive market condition will convince more people to start adopting a new marketplace whereas at the times of crisis, it is obvious that most people want to stay away from trying out new things.