[HayZee518]

The National Electrical Code established that the absolute minimum for residential service entrances is 100 amperes.
The figures you gave $800 and $1200 respectivbely for a 100 and 200 is just about right.
Materials for a 100 amp typically run about $325 for the panelbox, $18 for the meter socket, $12 for the weatherproof connector, $5.25 for the weatherhead etc.
The cable size is 2/3 aluminum SEU for 100 and 4/0-3 for a 200 amp and I've seen prices from $1.88 to 2.03 per foot.
The "Cadillac" of entrance panels can cost considerably more - Cutler-Hammer, Square "D" some Siemens panels and all panels with bolt in circuit breakers.
Mind you in changing out panels, the new code says you have to protect all bedroom circuits with arc-fault breakers. This started in Jan 1 2001.
Initially they were expensive but have come down drastically in price while maintaining their protection factor.