Does the limit of $2500 for the Safe Harbor election apply to the total cost of laptop or just the business portion?

Note: I'm a sole proprietor with no financial statements, so I understand my Safe Harbor limit is $2500 not $5000.

If I purchase a computer for 50% business use and the total shown on the receipt is $4800, am I disqualified from expensing the business portion of the laptop ($2400) due to the actual cost of the laptop (over $4800)?

Second question - is listed property used less than 50% for business automatically disqualified from Safe Harbor elections? (I'm aware that computers are no longer classified as listed property, I'm curious about other equipment I use, such as digital cameras. I use these about 25% for business)