When Sanford decided to buy half a downtown block last month for $450,000, city leaders said the purchase would give them more control over development along Lake Monroe. But although he voted to buy the land, which has been used as a public parking lot, Commissioner Randy Jones said he hopes the city won’t own it for long. Jones is among those who think the city owns too much real estate near the waterfront that could be sold for a multistory development, potentially bringing apartments, offices, parking garages, and upscale shopping and dining to Sanford’s old-Florida downtown.