I want to buy $100k worth of Bitcoin and move them to an exchange.
1. Are there better alternatives to Coinbase in terms of purchase fees and transaction?
2. Wouldnt it maybe be cheaper to buy LTC, move it to the exchange and buy BTC with it?
Now we're talking! We could use your investment right now!
There might be better alternatives to Coinbase, but first...what country do you live in? Your exchange options are driven by country of residence.
Here's a link to a site that offers comparisons of several, if not all, exchanges:
https://www.cryptocompare.com/exchanges/#/overview
It could be a bit cheaper to buy LTC, but mostly because the volatility is less than BTC. Bitcoin has had some wild swings. Litcoin is, right now, a better place to house some coin before you make your purchase.