WordPress Website: VERY SLOW SPEED.Need improvement

My wordpress site is extremely slow. I had some custom programming done for my booth rental process and since then, it is Very VERY slow. I feel this is not host related. It is hosted with Bluehost or justhost.com. Maybe its related to the database and needs to be optimized? I will remove all unwanted plugins to see if there is an improvement. Please let me know how much it will be to fix this.